/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements. See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership. The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the  "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
/*
 * $Id$
 */
package wx.xml.xalan.xalan.processor;

import org.xml.sax.Attributes;
import org.xml.sax.SAXException;

import wx.xml.xalan.xalan.templates.ElemExsltFuncResult;
import wx.xml.xalan.xalan.templates.ElemExsltFunction;
import wx.xml.xalan.xalan.templates.ElemParam;
import wx.xml.xalan.xalan.templates.ElemTemplateElement;
import wx.xml.xalan.xalan.templates.ElemVariable;

/**
 * This class processes parse events for an exslt func:result element.
 *
 * @xsl.usage internal
 */
public class ProcessorExsltFuncResult extends ProcessorTemplateElem {
    static final long serialVersionUID = 6451230911473482423L;

    /**
     * Verify that the func:result element does not appear within a variable,
     * parameter, or another func:result, and that it belongs to a func:function
     * element.
     */
    public void startElement(
        StylesheetHandler handler, String uri, String localName, String rawName, Attributes attributes)
        throws SAXException {
        String msg = "";

        super.startElement(handler, uri, localName, rawName, attributes);
        ElemTemplateElement ancestor = handler.getElemTemplateElement().getParentElem();
        while (ancestor != null && !(ancestor instanceof ElemExsltFunction)) {
            if (ancestor instanceof ElemVariable
                || ancestor instanceof ElemParam
                || ancestor instanceof ElemExsltFuncResult) {
                msg = "func:result cannot appear within a variable, parameter, or another func:result.";
                handler.error(msg, new SAXException(msg));
            }
            ancestor = ancestor.getParentElem();
        }
        if (ancestor == null) {
            msg = "func:result must appear in a func:function element";
            handler.error(msg, new SAXException(msg));
        }
    }
}
